Switch tube for controlling electric circuits



Nov. 29, 1927. 1,650,909

R. RUDENBERG swITcH TUBE FOR CONTROLLING ELECTRIC cmcuzws Filed 111132, 1925 Patented Nov. 29, 1927..

UNITED STATES 1,650,909 PATENT OFFICE.

REINHOLD Rfi'DENBERG, OF BERLIN-GRU'NEWALD, GERMANY, ASSIGNOIR. T SIEMENS- SGHUGKERTWERKE GESELLSCHAFT MIT IBESCHRANKTER HAFTUNG, OF SIEMENS- STAIJT, NEAR BERLIN, GERMANY, A COREORATION 0F GERMANY.

SWITCH.TUBE FOR CONTROLLING ELECTRIC CIRCUITS.

Application filed July 2, 1926, Serial No.

My invention relates to switch tubes for controlling electric circuits. It is well known to employ mercury vapor tubes for carrying out switching operations in electric a circuits. Such tubes have the great advan tage that they allow power current to pass easily. The switch tube may be provided with a positive as well as a negative mercury electrode or a negative electrode only.

in To initiate the passage of the current ignition electrodes in the form of ignition belts, rings and the like are provided at the electrodes inside or outside the tubes which ignition electrodes are excited from a source of it current of suitable voltage in order to start the arc.

In the arrangements heretofore used in the arc the ignition electrodes of the Vapor tube are excited with opposite polarities,

for instance by connecting them to the two ends of a coil in which current is induced through the main line current when it is interrupted. Practical experience has proven, however, that an arrangement in which the ignition electrodes have opposite polarity does not operate reliably. This may probably be accounted for by the fact that at the moment of ignition one of the ignition electrodes tends to strike an arc in the tube, but that the second electrode simultaneously exerts an extinguishing efiect.

My invention consists of a switch tube containingmercury vapor or similar metal vapors and having positive and negative electrodes or only a negative mercury electrode, in which both ignition electrodes of the tubes are excited with the same polarity in order to obtain a sure striking of the arc. Numerous experiments have proved that in this way a more realiable ignition of the tubes is obtained than in an arrangement or system, in which both ignition electrodes possess opposite polarities at the same moment.

The drawing illustrates an example of the novel manner in which the ignition electrodes may be excited. For this purpose the vapor tube 1 is provided with two mercury main electrodes 6 and 7. The tube is connected in parallel to the main switch 2 located in the line 3 to be interrupted, 4 and 5 represent the annular ignition electrodes of the tube. The secondary winding 9 of the transformer primary 14, connected in the 120,1 93, and. in Germany June 30, 1925.

main circuit, is here connected with one end at both ignition electrodes l and 5 in order to obtain the same polarity. The other end of the coil is connected with the two main electrodes 6 and 7 of the switch tube through two condensers 10 and 11. The ignition currents of the two ignition rings 4 and 5 can thus return independent of each other across these condensers and the main electrodes.

In the embodiments illustrated the ignition electrodes are excited by the secondary winding of an inductive coupling device. It will be readily understood, however, that any other suitable arrangement may be employed for exciting the ignition electrodes. A capacitive or a conductive coupling may thus equally well be used, for instance, all of which are known in the art as equivalents in this respect. It is, furthermore, immaterial whether, as shown, one switch tube with two mercury electrodes is employed or two tubes with one mercury cathode each. Further, I do not intend to limit myself to the exact details shown or described, but that ll intend to include as part of my invention all such obvious changes and modifications of parts as would suggest themselves to persons skilled in the art and as would fall within the scope of the claims.

I claim as my invention 1. A switch tube for breaking line circuits, having metal vapor filling and an ignition electrode at each of its poles and an ignition device including circuit connections with the line and said electrodes for charging said ignition electrodes with equal polarit 1 2. In a switch tube for breaking line circuits, having mercury vapor filling and an ignition electrode at each of its poles and an ignition device including circuit connections with the line and said electrodes for charging said ignition electrodes with equal polarity.

3. In a switch tube for breaking line circuits, having metal vapor filling, a positive and a negative mercury electrode, and an ignition electrode at each of its poles, and an ignition device including circuit connections with the line and said'electrodes for charging said ignition electrodes with equal polarity.

4. In a device for breaking line circuits the combination of a main switch, a switch tube ha two main electrodes and being connected 1n parallel relation to said main switch, ignition electrodes at both poles of said switch tube, a coil suitably related to the line to induce a current when the said main switch is opened, and electric connections between one end of said coil and both of said ignition electrodes, and other electric connections between the other end of said coil and both of said main electrodes of said switch tube.

5. In a device for breaking line circuits the combination of a main switch, a switch tube having two main electrodes and being connected in parallel relation to said main switch, ignition electrodes at both poles of said switch tube, a coil suitably related to the line to induce a current when the said main switch is opened, and electric connections between one end of said coil and both of said ignition electrodes, and other electric connections between the other end of said coil and both of said main electrodes of said switch tube, and a condenser placed in each of the latter connections.

6. In a device for breaking line circuits the combination of a main switch, a switch tube having two main electrodes and being connected in parallel relation to said main switch, ignition electrodes at both poles of said tube, a transformer having its primary winding connected in series with said main switch and an electric connection between one end of the secondary winding of said transformer and both ignition electrodes of said switch tube, and between the other secondary Winding end and the main tube electrodes, for exciting said ignition electrodes with equal polarity when current is induced in said secondary winding. I

7. In a device for breaking line circuits the combination of a main switch, a switch tube having two main electrodes and being connected in parallel relation to said switch, ignition electrodes at both poles of said tube, a transformer having its primary winding suitably connected with the line relatively to said main switch, to inductively respond to current changes occurring when said switch is opened, and a connection between the secondary transformer winding and said ignition electrodes by which they are excited at equal polarity when said secondary winding is excited by the inductive response of the primary winding.

In testimony whereof I aflix my signature.

REINHOLD RUDENBERG. 

